[0/5] Support hot-unbind in IOAT

Message

Logan Gunthorpe Dec. 16, 2019, 7:01 p.m. UTC

Hey,

This patchset creates some common infrastructure which I will use in the
next version of the PLX driver. It adds a reference count to the
dma_device struct which is taken and released every time a channel
is allocated or freed. A call back is used to allow the driver to
free the underlying memory and do any final cleanup.

For a use-case, I've adjusted the ioat driver to properly support
hot-unbind. The driver was already pretty close as it already had
a shutdown state; so it mostly only required freeing the memory
correctly and calling ioat_shutdown at the correct time.

This patchset is based on v5.5-rc2 and a git branch is available here:

https://github.com/sbates130272/linux-p2pmem/ ioat-hot-unbind

Thanks,

Logan

--

Logan Gunthorpe (5):
  dmaengine: Store module owner in dma_device struct
  dmaengine: Call module_put() after device_free_chan_resources()
  dmaengine: Move dma_channel_rebalance() infrastructure up in code
  dmaengine: Add reference counting to dma_device struct
  dmaengine: ioat: Support in-use unbind

 drivers/dma/dmaengine.c   | 352 +++++++++++++++++++++-----------------
 drivers/dma/ioat/init.c   |  38 ++--
 include/linux/dmaengine.h |  10 +-
 3 files changed, 233 insertions(+), 167 deletions(-)

--
2.20.1

Comments

Vinod Koul Dec. 24, 2019, 4:50 a.m. UTC | #1

On 16-12-19, 12:01, Logan Gunthorpe wrote:
> Hey,
> 
> This patchset creates some common infrastructure which I will use in the
> next version of the PLX driver. It adds a reference count to the
> dma_device struct which is taken and released every time a channel
> is allocated or freed. A call back is used to allow the driver to
> free the underlying memory and do any final cleanup.
> 
> For a use-case, I've adjusted the ioat driver to properly support
> hot-unbind. The driver was already pretty close as it already had
> a shutdown state; so it mostly only required freeing the memory
> correctly and calling ioat_shutdown at the correct time.

I didnt find anything else (apart from one change i pointed), so I have
applied this and will fix the comment. No point in delaying this

Logan Gunthorpe Dec. 25, 2019, 2:25 a.m. UTC | #2

On 2019-12-23 9:50 p.m., Vinod Koul wrote:
> On 16-12-19, 12:01, Logan Gunthorpe wrote:
>> Hey,
>>
>> This patchset creates some common infrastructure which I will use in the
>> next version of the PLX driver. It adds a reference count to the
>> dma_device struct which is taken and released every time a channel
>> is allocated or freed. A call back is used to allow the driver to
>> free the underlying memory and do any final cleanup.
>>
>> For a use-case, I've adjusted the ioat driver to properly support
>> hot-unbind. The driver was already pretty close as it already had
>> a shutdown state; so it mostly only required freeing the memory
>> correctly and calling ioat_shutdown at the correct time.
> 
> I didnt find anything else (apart from one change i pointed), so I have
> applied this and will fix the comment. No point in delaying this

Great, thanks!

Logan